Hi,
Some grading companies have a fixed price while some add an amount depending upon the value of the coin. Each of the major grading companies will have their price structures on their websites.
I am not sure of what your experience level is as you only have 34 posts....but....
That can mean that you just found us:-) even though you might have a ton of experience. OR...You may be pretty new at this.
The reality is that unless a coin is worth more than a hundred dollars, it doesn't pay to have a coin encapsulated. The next reality is that most people want to send in coins that they think are something important but the coins turn out to be damaged or exhibiting doubling called
Machine Doubling, which is worthless.
Many collectors attempting to slab coins, end up doing one of a few things.
1) paying a fee to have a coin come back as nothing.
2) paying a fee to have a worthless coin come back labeled as "machine doubled"
3) paying a fee worth much more than the coin is worth.
If you have experience then I would guess that you wouldn't be asking your original question so I am guessing that you are still in the learning phase of this fun hobby. I would sincerely reccommend that you really study your coins so that you fully know what you are looking at. In the hobby, we used to say "Buy the Book before the coin". The idea was that it is better to gain a strong knowledge base before spending money:-)
The same thing applies with respect to slabbing coins.
We are here to help! You can post pictures here or you can read the many posts here to determine what you might have and thereby make a good choice as to what you might want to spend your money on.
Have Fun,
Bill